Smart glass transmittance control system and method

ABSTRACT

A smart glass transmittance control system includes: a smart glass that decreases transmittance of the smart glass in response to the quantity of light introduced and increases the transmittance of the smart glass when electric power is applied; a power supply unit to supply the electric power to the smart glass; a control unit to control supply of the electric power from the power supply unit to the smart glass in order to control the transmittance of the smart glass according to a user request. In particular, the control unit controls the supply of the electric power from the power supply unit to the smart glass based on the driving environment of a vehicle, the quantity of light from an external light source, or the driving environment condition of the smart glass.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2019-0118586, filed on Sep. 26, 2019, the entirecontents of which are incorporated herein by reference.

FIELD

The present disclosure relates to a smart glass transmittance controlsystem and method, and more particularly to a smart glass transmittancecontrol system and method capable of discoloring or achromatizing asmart glass.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

Electrochromism is a phenomenon in which a color is reversibly changedby the direction of an electric field when voltage is applied, and anelectrochromic material is a material having optical properties whichare reversibly changeable by an electrochemical reduction-oxidationreaction. The electrochromic material has characteristics in which theelectrochromic material exhibits no color in the case in which noelectrical signal is applied from outside and exhibits a color when anelectrical signal is applied or in which the electrochromic materialexhibits a color in the case in which no signal is applied from outsideand is achromatized when a signal is applied.

An electrochromic device, which is a device using a phenomenon in whichtransmittance of the electrochromic material is changed by anelectrochemical reduction-oxidation reaction, is used to adjusttransmittance and reflectance of a window glass for buildings or avehicle mirror. In recent years, it has been known that anelectrochromic device has an infrared blocking effect as well asdiscoloration within a visible light region, whereby the electrochromicdevice has attracted great attention as possible energy-saving products.

Furthermore, in recent years, a vehicle glass is manufactured using theelectrochromic device in order to provide a smart glass, transmittanceof which is adjustable. A conventional smart glass is configured suchthat transmittance of the smart glass is controlled using polarizationtechnology through control of angular arrangement of materials whenelectricity is applied to liquid crystals and floating materials.

In a conventional glass or mirror using the electrochromic device,however, the function thereof is deteriorated depending on impuritiescontained in an electrochromic layer. Furthermore, power must becontinuously applied, whereby driving power of a vehicle is reduced.

Furthermore, in the case in which a smart glass configured such that thesmart glass is irreversibly discolored in the case in which a lightsource is present and the smart glass is achromatized only when power isapplied is mounted, a new method of controlling transmittance of thesmart glass is required.

The above information disclosed in this Background section is providedonly for enhancement of understanding of the background of the presentdisclosure and therefore it may contain information that does not formthe prior art that is already known to a person of ordinary skill in theart.

SUMMARY

The present disclosure provides a system and method for controlling asmart glass configured such that transmittance of the smart glass isautomatically decreased depending on the quantity of light applied tothe smart glass from outside.

Moreover, the present disclosure provides a smart glass transmittancecontrol system and method capable of discoloring and achromatizing thesmart glass based on the quantity of external light.

The objects of the present disclosure will be clearly understood fromthe following description and could be implemented by means defined inthe claims and a combination thereof.

In one aspect, the present disclosure provides a smart glasstransmittance control system including: a smart glass that decreasestransmittance of the smart glass in response to the quantity of lightintroduced and increases the transmittance of the smart glass whenelectric power is applied; a power supply unit configured to supply theelectric power to the smart glass; a control unit configured to controlsupply of the electric power from the power supply unit to the smartglass in order to control the transmittance of the smart glass accordingto a user request; wherein the control unit is configured to control thesupply of the electric power from the power supply unit to the smartglass based on a driving environment of a vehicle, the quantity of lightfrom an external light source, or a driving environment condition of thesmart glass.

The control unit may be configured to determine the transmittance of thesmart glass based on the quantity of light measured by an auto lightsensor or an ambient light sensor.

The control unit may be configured to determine the driving environmentof the vehicle through a navigation system.

The control unit may be configured to perform control such that power isapplied to the smart glass in response to a light blocking area on adriving route of the vehicle through the navigation system.

The control unit may be configured to perform control such that thetransmittance of the smart glass increases in the case in which noexternal light source is present.

In another aspect, the present disclosure provides a method ofcontrolling transmittance of the smart glass configured such thattransmittance of the smart glass decreases in response to the quantityof light introduced into a vehicle and the transmittance of the smartglass increases in the case in which electric power is applied. Inparticular, the method includes: determining, by a controller, a drivingenvironment condition of the smart glass; determining, by thecontroller, whether the quantity of light introduced is equal to or morethan a first reference value in the case in which the drivingenvironment condition is an automatic mode; entering, by the controller,a day mode in the case in which the quantity of light introduced isequal to or more than the first reference value and determining whetherthe quantity of light introduced exceeds a second reference value;decreasing, by the controller, the transmittance of the smart glass inthe case in which the quantity of light introduced exceeds the secondreference value; and applying, by the controller, the electric power tothe smart glass in the case in which the quantity of light introducedexceeds the second reference value and setting a hysteresis period inthe case in which the transmittance of the smart glass is equal to ormore than intermediate brightness level.

The method may further include: entering, by the controller, a nightmode in the case in which the quantity of light introduced is less thanthe first reference value, and determining whether the quantity of lightintroduced is equal to or less than a third reference value; applying,by the controller, the electric power to the smart glass in the case inwhich the quantity of light introduced is equal to or less than thethird reference value, and determining whether the quantity of lighttransmitted through the smart glass is equal to or more than the thirdreference value; and turning the electric power off in the case in whichthe quantity of light transmitted through the smart glass is equal to ormore than the third reference value.

The step of applying power to the smart glass and determining whetherthe quantity of light transmitted through the smart glass is equal to ormore than the third reference value may include applying the power tothe smart glass in a pulse form in the case in which the quantity oflight introduced is equal to or less than the third reference value.

The step of determining the driving environment condition of the smartglass may include determining whether an external light blocking area ispresent on a driving route of the vehicle and applying maximum power tothe smart glass in the case in which the external light blocking area ispresent on the driving route.

The step of determining the driving environment condition of the smartglass may include determining whether the quantity of light introducedexceeds the second reference value in the case in which the drivingenvironment condition is a self-driving mode or a private mode anddetermining whether the transmittance of the smart glass is the lowestbrightness level in the case in which the quantity of light introducedexceeds the second reference value.

The power may be turned off in the case in which the transmittance ofthe smart glass is the lowest brightness level.

The step of determining the driving environment condition of the smartglass may include determining whether paling is sensed by at least oneof the smart glass or a light quantity sensor and applying power inorder to switch the transmittance of the smart glass to the higheststate in the case in which the paling is sensed.

The step of determining whether paling is sensed may include generatinga paling signal in the case in which the paling is sensed.

The step of determining the driving environment condition of the smartglass may include determining whether the driving environment conditionis a parked state in the automatic mode, determining whether thequantity of light introduced in the automatic mode is less than thefirst reference value and is equal to or less than a third referencevalue, applying power to the smart glass in the case in which thequantity of light introduced is less than the first reference value andis equal to or less than the third reference value, and turning poweroff in the case in which the quantity of light transmitted through thepowered smart glass is equal to or more than the third reference valueand continuously applying power in the case in which the quantity oflight transmitted through the powered smart glass is less than the thirdreference value.

The step of determining the driving environment condition of the smartglass may include determining whether there is user switch input in thecase in which the driving environment condition is a manual mode,determining whether the quantity of light introduced is equal to or morethan a third reference value in the case in which there is the userswitch input, determining whether the quantity of light transmittedthrough the smart glass is less than the third reference value in thecase in which the quantity of light introduced is equal to or more thanthe third reference value, and applying power in the case in which thequantity of light transmitted through the smart glass is less than thethird reference value.

The smart glass transmittance control system may further include turningpower off in the case in which the quantity of light transmitted throughthe smart glass is equal to or more than the third reference value.

The step of determining whether the quantity of light transmittedthrough the smart glass is less than the third reference value in thecase in which the quantity of light introduced is equal to or more thanthe third reference value may include applying power in the case inwhich the quantity of light transmitted through the smart glass is lessthan the third reference value.

The step of determining whether the quantity of light transmittedthrough the smart glass is less than the third reference value mayinclude turning power off in the case in which the quantity of lighttransmitted through the smart glass is equal to the third referencevalue.

The step of determining whether the quantity of light transmittedthrough the smart glass is less than the third reference value mayinclude displaying impossibility of execution in the case in which thequantity of light transmitted through the smart glass exceeds the thirdreference value.

The driving environment condition may be measured using at least one ofan auto light sensor, a rain sensor, a navigator, or an ambient lightsensor located inside the smart glass.

Other aspects and exemplary forms of the present disclosure arediscussed infra.

It is understood that the term “vehicle” or “vehicular” or other similarterm as used herein is inclusive of motor vehicles in general such aspassenger automobiles including sports utility vehicles (SUV), buses,trucks, various commercial vehicles, watercraft including a variety ofboats and ships, aircraft, and the like, and includes hybrid vehicles,electric vehicles, plug-in hybrid electric vehicles, hydrogen-poweredvehicles and other alternative fuel vehicles (e.g. fuels derived fromresources other than petroleum). As referred to herein, a hybrid vehicleis a vehicle that has two or more sources of power, for example bothgasoline-powered and electric-powered vehicles.

The statements in this section merely provide background informationrelated to the present disclosure and may not constitute prior art.

DRAWINGS

In order that the disclosure may be well understood, there will now bedescribed various forms thereof, given by way of example, referencebeing made to the accompanying drawings, in which:

FIG. 1 is a block diagram showing a smart glass transmittance controlsystem in one form of the present disclosure;

FIG. 2 is a graph showing the relationship between factors forcontrolling smart glass transmittance;

FIG. 3 is a flowchart showing a smart glass transmittance control methodaccording to one form of the present disclosure;

FIG. 4 is a flowchart showing the smart glass transmittance controlmethod in a self-driving or private mode;

FIG. 5 is a flowchart showing the smart glass transmittance controlmethod in a parked state; and

FIG. 6 is a flowchart showing the smart glass transmittance controlmethod in a manual mode.

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses. Itshould be understood that throughout the drawings, correspondingreference numerals indicate like or corresponding parts and features.

Reference will now be made in detail to various forms of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings and described below. However, the present disclosure may beembodied in many different forms and should not be construed as limitedto the forms set forth herein. Rather, these forms are provided so thatthis disclosure will be thorough and complete, and will fully convey thescope of the disclosure to those skilled in the art.

It should be understood that the appended drawings are not necessarilyto scale, presenting a somewhat simplified representation of variousfeatures illustrative of the basic principles of the present disclosure.The specific design features of the present disclosure as disclosedherein, including, for example, specific dimensions, orientations,locations, and shapes, will be determined in part by the particularintended application and use environment.

In addition, the term “unit,” “sensor” or “glass” used in thisspecification signifies one unit that processes at least one function oroperation, and may be realized by hardware, software, or a combinationthereof.

In addition, relational terms, such as “first” and “second,” are used inthis specification only to distinguish between the same elements, andthe elements are not limited as to the sequence therebetween in thefollowing description.

In addition, the term “light source” used in this specification includesall constructions configured to apply light to a vehicle. In thisspecification, sunlight is described as being a light source as oneform; however, the light source is not limited thereto.

Also, in this specification, the term “discoloration” means thattransmittance of a smart glass is controlled so as to decrease, and theterm “achromatization” means that transmittance of the smart glass iscontrolled so as to increase.

Also, in this specification, transmittance of the smart glass may bedefined as meaning the quantity B of light introduced into the smartglass.

The present disclosure relates to a smart glass configured to bediscolored in response to the quantity A of light introduced fromoutside, wherein in the case in which the quantity of light incidentfrom outside, such as the sun, is equal to or more than a secondreference value a″, the smart glass is discolored such thattransmittance of the smart glass decreases.

In addition, in the case in which electric power is applied to the smartglass, the discolored smart glass is achromatized, whereby transmittanceof the smart glass increases.

In brief, the smart glass according to the present disclosure isconfigured to be irreversibly discolored in the case in which a lightsource is present. In one form, the smart glass is discolored inresponse to the quantity of light introduced from the light source, andseparate power (i.e., electric power) is applied in order to achromatizethe smart glass.

FIG. 1 is a view showing coupling between components of a smart glasstransmittance control system according to one form of the presentdisclosure.

A control unit 100 located in a vehicle is configured to measure thequantity of light introduced from outside through an auto light sensor200 and a rain sensor 300 and to measure whether the vehicle self-drivesthrough a self-driving sensor 500.

In addition, the control unit 100 is configured to be linked to adisplay unit 600 located inside the vehicle, and is configured todisplay the current state of a smart glass 700 depending on drivingthereof or to perform input for controlling the smart glass 700.

In one form of the present disclosure, the display unit 600 may beconfigured to display the driving state of the smart glass 700, whetherthe smart glass is paled, and whether the smart glass is discolored.

In another form, the control unit 100 may be divided into a vehiclecontroller 120 and a controller 110 configured to control the smartglass 700. The vehicle controller 120 may be configured to be linked tothe auto light sensor 200, the rain sensor 300, a navigator 400, and theself-driving sensor 500.

An ambient light sensor 800 is located inside the smart glass 700, andis configured to measure the quantity of light introduced into thevehicle depending on discoloration of the smart glass 700, and isconfigured to measure the quantity of light introduced into the vehiclefrom a light source through the smart glass 700 in order to determinetransmittance of the smart glass 700.

In addition, the ambient light sensor 800 is connected to the controlunit 100 of the vehicle to measure the quantity of light introduced intothe vehicle and to perform discoloration or achromatization of the smartglass 700 through the control unit 100 based on the measured lightquantity data.

The smart glass controller 110 is connected to the vehicle controller120 to receive information of the sensors and the navigator 400 locatedin the vehicle and to perform control such that power is applied to thesmart glass 700 through the smart glass controller 110, and isconfigured to control the discoloration quantity of the smart glass 700according to a user request.

In addition, the vehicle controller 120 is configured to be linked to atransmittance variable adjustment switch 710, and is configured toreceive a transmittance change value from a user and to transmit acontrol command to the controller of the smart glass 700 in responsethereto.

In addition, the transmittance variable adjustment switch 710 isconfigured to input a manual mode, an automatic mode, a self-drivingmode, or a private mode as a driving environment condition of the smartglass 700.

The navigator 400 is configured to determine a light blocking arealocated on a driving route of the vehicle. In the case in which thevehicle is near the light blocking area, maximum electric power isapplied to the smart glass 700 such that the smart glass 700 isachromatized in the state in which transmittance is the highest.

A tunnel may be confirmed using two methods. A first method is todetermine the state before entering the tunnel and the state afterentering the tunnel using a GPS system or a navigation system of thevehicle. A second method is to analyze the difference between an ambientlight value in front of the auto light sensor and an ambient light valueabove the auto light sensor in order to determine whether the tunnel hasbeen sensed (before entry) and whether the vehicle has entered thetunnel.

As described above, the smart glass of the present disclosure isconfigured to control the discoloration of the smart glass based on adriving environment of the vehicle such as the state of a road on whichthe vehicle is traveling.

In one form, the vehicle including the smart glass 700 may determine aday mode and a night mode. In the case in which the quantity of lightintroduced from outside is equal to or more than a first reference valueDN, it is determined to be the day mode. In the case in which thequantity of light introduced from outside is less than the firstreference value DN, it is determined to be the night mode.

In the day mode, the light source is located outside, and therefore thesmart glass 700 is basically configured to be discolored. In the nightmode, no separate light source is present, and therefore transmittanceof the smart glass 700 is controlled in the state in which additionaldiscoloration is impossible.

In the day mode, when the quantity of light introduced from outside ismore than a second reference value a″, the smart glass is additionallydiscolored.

Furthermore, in the night mode, when the quantity of light introducedfrom outside is equal to or less than a third reference value a′,electric power is applied to the smart glass 700 such that the smartglass 700 is achromatized.

In the case in which the quantity of light transmitted through theachromatized smart glass 700 is equal to or more than the thirdreference value a′, power is switched to an off state. In the nightmode, therefore, achromatization is performed in the case in which thequantity of light introduced is equal to or less than the thirdreference value a′, and achromatization is stopped in the case in whichthe quantity of light transmitted through the smart glass is more thanthe third reference value a′.

The third reference value is set as a reference value to achromatize thesmart glass 700 based on the quantity of light measured by the autolight sensor 200. Furthermore, the third reference value is set as areference value of transmittance of light introduced into the smartglass 700 and measured by the ambient light sensor 800.

In brief, in the day mode, in which the light source is present, in thecase in which the quantity of light introduced is more than the secondreference value a″, which is a discoloration criterion, the smart glass700 is discolored, and in the night mode, in the case in which thequantity of light introduced is equal to or less than the thirdreference value a′, which is an achromatization criterion, the smartglass 700 is achromatized.

As another form of the present disclosure, FIG. 2 shows thediscoloration criterion and the achromatization criterion of the smartglass 700, which is a graph showing switching between the day mode andthe night mode over time.

As shown, in the case in which the quantity of light introduced is equalto or more than the first reference value DN, the day mode is set, andin the case in which the quantity of light introduced is less than thefirst reference value DN, the night mode is set. The day mode is shownat the front end and the rear end of the graph, and the night mode isshown at the middle of the graph.

Furthermore, the third reference value is set for a discoloration periodso as to have larger quantity of light than the first reference value,the second reference value is set for an achromatization period so as tohave smaller quantity of light than the first reference value, and ahysteresis period is set between the second reference value and thethird reference value (periodic repetition of discoloration andachromatization being limited).

In the hysteresis period, the quantity of light transmitted through thesmart glass is maintained at intermediate brightness level MTP, at whichdiscoloration transmittance and achromatization transmittance areintermediate, thereby securing safety. The intermediate brightness levelMTP is adjustable within a transmittance range.

Furthermore, the hysteresis period may include a predetermined period inwhich the smart glass 700 is neither achromatized nor discolored by anexternal light source and the quantity of light introduced into thesmart glass 700, and means a period between high brightness level UTP,at which the quantity of light introduced into the smart glass 700 islarge, and low brightness level LTP, at which the quantity of lightintroduced into the smart glass 700 is small.

In another form of the present disclosure, in the day mode in anautomatic mode state, in the case in which the quantity of lightintroduced exceeds the second reference value a″, which is thediscoloration criterion, the smart glass 700 is discolored.

In addition, in the case in which the mode is determined to be the nightmode in the automatic mode control state, in the case in which thequantity of light introduced is equal to or less than the thirdreference value a′, which is the achromatization criterion, the smartglass 700 is achromatized in order to increase the quantity of lighttransmitted through the smart glass 700.

In one form of the present disclosure, the control unit 100 may beconfigured to compare the quantity of light introduced with thediscoloration criterion and the achromatization criterion and to performdiscoloration and achromatization depending on the driving environmentcondition.

Furthermore, a construction in which unit-pulse type power is applied inthe night mode is shown at the middle region of FIG. 2.

In the night mode, in the case in which the quantity of lighttransmitted through the smart glass 700 is more than a third referencevalue a′ (the achromatization criterion) in the state in which thequantity of light introduced is equal to or less than the thirdreference value a′, electric power is applied to the smart glass 700 inorder to achromatize the smart glass.

Furthermore, in the night mode, in which no external light source ispresent, it is not possible to selectively discolor the smart glass 700,which is irreversibly discolored compared to the external light source,and therefore pulse power is applied such that the quantity of lighttransmitted through the smart glass has the same value as anachromatization criterion value.

The quantity of light transmitted through the smart glass 700 iscompared with the third reference value a′ in order to apply pulsepower. That is, in order to perform rapid achromatization, as the thirdreference value a′ approaches the maximum brightness level of theachromatization transmittance, a single relatively long pulse width isincreased, whereby the discolored smart glass 700 is rapidlyachromatized, and as the third reference value a′ approaches the lowbrightness level of the achromatization transmittance, operation isperformed at a short pulse width, whereby power consumption of thevehicle for the same operating time is reduced.

That is, the cycle and intensity of the pulse applied to performachromatization may vary depending on the difference between the thirdreference value a′ and a range value of light introduced into the smartglass 700.

In one form of the present disclosure, in the case in which the quantityof light transmitted through the achromatized smart glass 700 in thenight mode is equal to or more than the third reference value a′,application of power is finished. That is, the smart glass 700 isachromatized in order to easily recognize the outside of the vehicle inthe state in which no external light source is present (the night mode),and in the case in which the quantity of light transmitted through thesmart glass 700 is equal to or more than the third reference value a′after achromatization, power applied to the smart glass 700 is turnedoff.

In some forms of the present disclosure, the first reference value DN isa reference point to distinguish between day and night and is defined asa value of the quantity of light incident onto the auto light sensor 200of the vehicle, and the third reference value a′ is a reference point ofachromatization and is configured to be a value lower than the firstreference point as the quantity of light incident onto the auto lightsensor 200 of the vehicle.

In addition, the second reference value a″ is a reference point ofdiscoloration and is set to a value higher than the first referencepoint as the quantity of light incident onto the auto light sensor 200of the vehicle. The quantity B of light measured by the ambient lightsensor 800 in the smart glass 700 is measured within a predeterminedtransmittance range of the smart glass. Values of B are set to highbrightness level UTP, low brightness level LTP, and intermediatebrightness level MTP. The high brightness level UTP and the lowbrightness level LTP are fixed variables in the system, and theintermediate brightness level MTP may be set within a range of the fixedvariables.

The smart glass set in an automatic mode first determines whether thevehicle has entered a tunnel in order to secure safety of the vehicle.In the case in which the tunnel is sensed or the vehicle has entered thetunnel, maximum power is applied to the smart glass 700 such that theglass is kept maximally bright through continuous application of power.

After the vehicle exits the tunnel, day and night are determined throughthe first reference value. In the day mode, in the case in which thequantity of light incident through the auto light sensor 200 of thevehicle is more than the second reference value a″, the smart glass 700is automatically discolored, and the operation is finished.

However, in the case which the quantity of light incident through theauto light sensor 200 of the vehicle is less than the second referencevalue a″ after the vehicle exits the tunnel, the quantity of lighttransmitted through the smart glass 700 is maintained at theintermediate brightness level MTP.

In the night mode, in the case in which the quantity of light introducedinto the smart glass 700 having the intermediate brightness level isless than the third reference value a′, power is applied to the smartglass 700 in order to achromatize the smart glass.

In the day mode, in the case in which the quantity A of light fromoutside measured through the auto light sensor 200 is equal to or lessthan the second reference value a″, power is applied, whether thequantity of light introduced into the smart glass 700 is equal to ormore than the intermediate brightness level is determined, and upondetermining that the quantity of light introduced into the smart glass700 is equal to or more than the intermediate brightness level, ahysteresis period is set such that the quantity of light introducedthrough the smart glass 700 is maintained at the intermediate brightnesslevel.

Under the same condition as above, in the case in which a light blockingarea is present on a route input into the navigator 400, power isapplied to achromatize the smart glass 700. Maximum power is applied tothe smart glass 700.

That is, in an area at which a light source is blocked, such as atunnel, in the case in which the vehicle instantaneously drives to adark area, it is desired to perform rapid achromatization, and thereforemaximum power from a power supply unit 900 is applied to the smart glass700 in order to rapidly achromatize the smart glass 700.

FIG. 3 is a flowchart showing a method of controlling transmittance ofthe smart glass 700 according to one form of the present disclosure.

As shown, the control unit 100 determines a driving environmentcondition of the smart glass 700 (S100), and in the case in which thedriving environment condition is set to an automatic mode (S200),determines whether a light blocking area is present (S210).

In the case in which no light blocking area is present, the control unitdetermines whether the quantity of light introduced from outside isequal to or more than a first reference value (S220). The firstreference value is a reference value to distinguish between a day modeand a night mode of the smart glass 700 based on the quantity ofexternal light.

In the case in which no light blocking area is present and the quantityof light introduced from outside is equal to or more than the firstreference value, the smart glass 700 enters the day mode (S230). Thesmart glass 700 that has entered the day mode determines whether thequantity of external light exceeds a second reference value a″ (S240),and in the case in which the quantity of external light exceeds thesecond reference value a″, the smart glass 700 is discolored (S250).

In the case in which the quantity of external light is equal to or lessthan the second reference value a″ (S240), power is applied to the smartglass 700 (S241), whether the quantity of light transmitted through thesmart glass 700 is equal to or more than intermediate brightness level(S242), and in the case in which the quantity of light transmittedthrough the smart glass 700 is equal to or more than intermediatebrightness level, the period is determined to be a hysteresis period(S243).

Unlike this, in the case in which no light blocking area is present andthe quantity of light introduced from outside is less than the firstreference value, the smart glass 700 enters the night mode (S310).

In the state in which the smart glass 700 has entered the night mode,whether the quantity of external light is equal to or less than a thirdreference value a′ is determined (S320), and in the case in which thequantity of external light is equal to or less than the third referencevalue a′, power from the power supply unit 900 is applied to the smartglass 700 (S330).

In the case in which the quantity of light transmitted through the smartglass 700 achromatized as the result of application of power is equal toor more than the third reference value a′ (S340), power is turned off(S350), and in the case in which the quantity of light transmittedthrough the achromatized smart glass 700 is less than the thirdreference value a′ (S340), power is continuously applied to the smartglass (S330).

The third reference value a′ is a reference value to achromatize thesmart glass 700. In the case in which the quantity of light applied fromoutside is small, it is difficult for a user to secure an external fieldof vision through the achromatized smart glass 700. Consequently, thethird reference value a′ is a value set to achromatize the smart glass700.

In addition, in another form of the present disclosure, whether a lightblocking area is present is determined (S210), and in the case in whichthe light blocking area is present, maximum power from the power supplyunit 900 is applied to the smart glass 700 in order to achromatize thesmart glass 700.

Subsequently, whether the vehicle has exited the light blocking area isdetermined (S212), and in the case in which the vehicle has exited thelight blocking area (S212), power is turned off (S213).

FIG. 4 is a flowchart showing another form of the present disclosure inthe case in which the driving environment condition is a self-driving orprivate mode.

Whether the mode input to the transmittance variable adjustment switch710 or a separate input device according to a user request is anautomatic mode is determined (S400), and in addition whether the drivingenvironment condition is a private mode or a self-driving mode isdetermined (S100).

In the case in which the driving environment condition is a self-drivingmode or a private mode in the automatic mode of the smart glass 700(S100), whether the driving state of the smart glass 700 is normal isdetermined (S410), and in the case in which the driving state of thesmart glass 700 is normal, whether the quantity of external lightexceeds the second reference value a″ is determined (S420).

In the case in which the quantity of external light exceeds the secondreference value a″, irreversible discoloration of the smart glass 700 isperformed (S430), and whether the transmittance of the smart glass 700is the lowest brightness level is determined (S440).

Furthermore, in the case in which the transmittance of the discoloredsmart glass 700 is equal to the lowest brightness level, the powersupply unit 900 is turned off (S450).

As described above, transmittance is maintained the lowest in theself-driving mode or the private mode, whereby the smart glass 700 isset such that it is difficult to recognize the interior of the vehiclefrom outside.

However, at the step of determining the driving state of the smart glass700, in the case in which the driving state of the smart glass 700 isnot normal (S500), whether the smart glass 700 is paled is determined(S510).

In the case in which the smart glass 700 is paled, an emergency signalis applied (S520), and power is continuously applied to the smart glass700 such that the transmittance of the smart glass 700 is the highest(S540).

That is, in the case in which it is detected that the smart glass 700 ispaled, which is a situation in which it is difficult to reflect a userrequest value, the smart glass 700 is controlled such that thetransmittance thereof is maximized, whereby stable driving of thevehicle is performed.

As described above, in the case in which the driving environmentcondition of the smart glass 700 is the private mode or the self-drivingmode, achromatization of the smart glass 700 is prevented even in thecase in which no light source is present, whereby the transmittance ofthe smart glass 700 is maintained low.

FIG. 5 is a flowchart showing a method of controlling transmittance ofthe smart glass 700 in a parking condition of the vehicle.

In the case in which the vehicle is turned off as a parking statecondition of the vehicle equipped with the smart glass 700 (S600), acount value is set to 0, and the driving environment condition (mode) ofthe smart glass 700 is confirmed (S610).

In the case in which a private mode is set as the driving environmentcondition at the time of parking (S620), power is turned off in thestate in which vehicle is off, whereby parking is completed withoutachromatization of the smart glass 700 (S621).

In the case in which the driving environment condition at the time ofparking is an automatic mode (S630), however, whether the quantity ofexternal light is less than the first reference value (S631), and in thecase in which the quantity of external light is equal to or more thanthe first reference value, operation is finished in the state in whichpower is off.

Unlike this, in the case in which the quantity of external light is lessthan the first reference value (S631), whether the quantity of externallight is less than a third reference value a′ (S632), and in the case inwhich the quantity of external light is less than the third referencevalue a′, unit power is applied to the smart glass 700 through the powersupply unit 900 (S633).

Furthermore, when the unit power is applied (S633), a set count value isincreased, in the case in which the increased count value is less than apredetermined setting value (S634), whether the quantity of lighttransmitted through the smart glass 700 is equal to or more than thethird reference value a′ is determined (S635).

In one form of the present disclosure, whether the count value is lessthan 2000 as the predetermined setting value is determined (S634), andin the case in which the count value is less than 2000 and in the casein which the quantity of light transmitted through the smart glass 700is equal to or more than the third reference value a′ (S635), power isturned off (S621). In the case in which the quantity of lighttransmitted through the smart glass 700 is not equal to or more than thethird reference value a′ (S635), unit power is additionally applied tothe smart glass 700 (S633).

Whether the count value is less than 2000 as the predetermined settingvalue is determined (S634), and in the case in which the count value isequal to or more than 2000, additional control is not performed, and thesystem is turned off in order to prevent power consumption.

In the case in which the driving environment condition is a manual mode(S640), whether the quantity of light transmitted through the smartglass 700 is less than the third reference value a′ is determined(S641), and in the case in which the quantity of light transmittedthrough the smart glass 700 is less than the third reference value a′,unit power is additionally applied to the smart glass 700 and at thesame time the count value is increased (S643).

Unlike this, in the case in which the quantity of light transmittedthrough the smart glass 700 is equal to or more than the third referencevalue a′, power is turned off (S644).

In addition, after the unit power is applied to the smart glass 700 andat the same time the count value is increased (S643), in the case inwhich the count value is less than the predetermined setting value(S645), whether the quantity of light transmitted through the smartglass 700 is less than the third reference value a′ is determined again(S641), and in the case in which the count value is equal to or morethan the predetermined setting value (S645), the system is turned off(S650).

In conclusion, in the case in which the vehicle is parked in the statein which the smart glass 700 is in the automatic mode, the discolorationof the smart glass is maintained in order to block heat from an externallight source in the daytime, and the set transmittance of the smartglass is maintained at night.

In addition, in the case in which the vehicle is parked in the state inwhich the smart glass 700 is in the manual mode, the smart glass 700 isset in order to maintain transmittance requested by the user.

Furthermore, at each step, unit power is applied to the smart glass 700while preventing discharge of the battery in order to achromatize thesmart glass 700.

FIG. 6 is a flowchart showing a method of performing discoloration orachromatization of the smart glass 700 in the state in which a userrequest for discoloration or achromatization is applied in the case inwhich the driving environment condition is a manual mode.

In the case in which the driving environment condition of the smartglass 700 is set to a manual mode (S100) and in which switch input isapplied according to user input and a discoloration request or anachromatization request (input of a change value) is applied to thecontrol unit 100 (S700), the quantity A of light introduced from outsidemeasured by the auto light sensor 200, transmittance of the smart glass700 based on the quantity of light introduced into the vehicle measuredby the ambient light sensor 800, and a third reference value a′ as afixed transmittance value are set (S710).

Subsequently, whether the quantity of light measured by the auto lightsensor 200 is equal to or more than the third reference value a′ isdetermined (S720), and in the case in which the quantity of light isequal to or more than the third reference value a′, whether the quantityB of light transmitted through the smart glass 700 is less than thethird reference value a′ is determined (S721).

In the case in which the quantity of light transmitted through the smartglass 700 is less than the third reference value a′, an indicatordisposed at a cluster of the vehicle or a position at which userrecognition is possible emits blue light, and power is applied to thesmart glass 700 (S722). As described above, the indicator, which is anindication device informing that transmittance is being changed to theuser request value, emits blue light.

Unlike this, in the case in which the quantity of light transmittedthrough the smart glass 700 is not less than the third reference valuea′ (S723), the indicator emits green light, and power is turned off(S724). In the case in which the indicator emits green light, it meansthat discoloration or achromatization of the smart glass 700 to desiredtransmittance has been completed.

At the step of determining whether the quantity of light introduced isequal to or more than the third reference value a′ (S720), in the casein which the quantity of light introduced is less than the thirdreference value a′ (S730), whether the quantity of light transmittedthrough the smart glass 700 is less than the third reference value a′ isdetermined (S731).

In the case in which the quantity of light transmitted through the smartglass 700 is less than the third reference value a′ (S731), theindicator emits blue light in order to inform that transmittance isbeing changed to the user request value, and power is applied to thesmart glass 700 (S732).

Unlike this, in the case in which the quantity of light transmittedthrough the smart glass 700 is equal to the third reference value a′(S733), the indicator emits green light in order to inform thatdiscoloration or achromatization of the smart glass 700 to desiredtransmittance has been completed (S734).

Furthermore, in the case in which the quantity of light transmittedthrough the smart glass 700 exceeds the third reference value a′ (S735),the indicator emits red light in order to inform that approach to thedesired transmittance is not possible (S736).

That is, in the case in which the indicator emits red light, it includesthe case in which it is requested that discoloration of the smart glass700 be performed in the state in which no external light source ispresent. That is, in the case in which no light source is present, thismeans the case in which further discoloration of the smart glass 700 isnot possible due to the feature of the smart glass 700, discoloration ofwhich is performed only in the case in which an external light source ispresent.

As described above, in the manual mode, achromatization anddiscoloration of the smart glass 700 are performed according to the userinput value. In the case in which no external light source is present,discoloration of the smart glass 700 is not possible due to the featureof the smart glass 700.

As is apparent from the foregoing, the present disclosure may have thefollowing effects.

The present disclosure provides a method of controlling discolorationand achromatization of the smart glass, which is irreversibly discoloredby an external light source, whereby it is possible to achieve stablepower driving of the vehicle.

In addition, according to the present disclosure, discoloration orachromatization of the smart glass is performed in response to variousdriving environment conditions, whereby it is possible to easily securea user's field of view.

The effects of the present disclosure are not limited to those mentionedabove. It should be understood that the effects of the presentdisclosure include all effects that can be inferred from the foregoingdescription of the present disclosure.

The foregoing describes exemplary forms of the present disclosure. Thepresent disclosure may be used in various different combinations,changes, and environments. That is, variations or modifications can bemade within the conceptual scope of the present disclosure, equivalentsto the disclosure of the present disclosure, and/or the scope oftechnology and knowledge in the art to which the present disclosurepertains. Therefore, the above detailed description does not limit thepresent disclosure disclosed above.

What is claimed is:
 1. A smart glass transmittance control systemcomprising: a smart glass configured to decrease transmittance of thesmart glass in response to a quantity of light introduced and increasethe transmittance of the smart glass when electric power is supplied; apower supply unit configured to supply the electric power to the smartglass; and a control unit configured to: control supply of the electricpower from the power supply unit to the smart glass to control thetransmittance of the smart glass according to a user request, whereinthe control unit is configured to control the supply of the electricpower to the smart glass based on a driving environment of a vehicle, aquantity of light from an external light source, or a drivingenvironment condition of the smart glass.
 2. The smart glasstransmittance control system according to claim 1, wherein the controlunit is configured to determine the transmittance of the smart glassbased on a quantity of light measured by an auto light sensor or anambient light sensor.
 3. The smart glass transmittance control systemaccording to claim 1, wherein the control unit is configured todetermine the driving environment of the vehicle through a navigationsystem.
 4. The smart glass transmittance control system according toclaim 3, wherein the control unit is configured to control the supply ofthe electric power to the smart glass in response to a light blockingarea on a driving route of the vehicle through the navigation system. 5.The smart glass transmittance control system according to claim 1,wherein the control unit is configured to increase the transmittance ofthe smart glass when no external light source is present.
 6. A method ofcontrolling transmittance of a smart glass, where the smart glassdecreases transmittance of the smart glass in response to a quantity oflight introduced into a vehicle and increases the transmittance of thesmart glass when electric power is applied, the method comprising:determining, by a controller, a driving environment condition of thesmart glass; when the driving environment condition is an automaticmode, determining, by the controller, whether the quantity of lightintroduced is equal to or greater than a first reference value;entering, by the controller, a day mode when the quantity of lightintroduced is equal to or greater than the first reference value, anddetermining whether the quantity of light introduced exceeds a secondreference value; decreasing, by the controller, the transmittance of thesmart glass when the quantity of light introduced exceeds the secondreference value; and applying, by the controller, the electric power tothe smart glass when the quantity of light introduced exceeds the secondreference value, and setting a hysteresis period when the transmittanceof the smart glass is equal to or greater than an intermediatebrightness level.
 7. The method according to claim 6, furthercomprising: entering, by the controller, a night mode when the quantityof light introduced is less than the first reference value, anddetermining whether the quantity of light introduced is equal to or lessthan a third reference value; applying, by the controller, the electricpower to the smart glass when the quantity of light introduced is equalto or less than the third reference value, and determining whether aquantity of light transmitted through the smart glass is equal to orgreater than the third reference value; and when the quantity of lighttransmitted through the smart glass is equal to or greater than thethird reference value, turning power off by the controller.
 8. Themethod according to claim 7, wherein applying the electric power to thesmart glass comprises applying the electric power to the smart glass ina pulse form when the quantity of light introduced is equal to or lessthan the third reference value.
 9. The method according to claim 6,wherein determining the driving environment condition of the smart glasscomprises: determining whether an external light blocking area ispresent on a driving route of the vehicle; and applying maximum power tothe smart glass when the external light blocking area is present on thedriving route.
 10. The method according to claim 6, wherein determiningthe driving environment condition of the smart glass comprises: when thedriving environment condition is a self-driving mode or a private mode,determining whether the quantity of light introduced exceeds the secondreference value; and when the quantity of light introduced exceeds thesecond reference value, determining whether the transmittance of thesmart glass is a lowest brightness level.
 11. The method according toclaim 10, wherein the electric power is turned off when thetransmittance of the smart glass is the lowest brightness level.
 12. Themethod according to claim 6, wherein determining the driving environmentcondition of the smart glass comprises: determining whether paling issensed by at least one of the smart glass or a light quantity sensor;and when the paling is sensed, applying the electric power to switch thetransmittance of the smart glass to a highest state.
 13. The methodaccording to claim 12, wherein determining whether paling is sensedcomprises generating a paling signal when the paling is sensed.
 14. Themethod according to claim 6, wherein determining the driving environmentcondition of the smart glass comprises: determining whether the drivingenvironment condition is a parked state in the automatic mode;determining whether the quantity of light introduced in the automaticmode is less than the first reference value and is equal to or less thana third reference value; when the quantity of light introduced is lessthan the first reference value and is equal to or less than the thirdreference value, applying the electric power to the smart glass; whenthe quantity of light transmitted through the powered smart glass isequal to or greater than the third reference value, turning the electricpower off; and when the quantity of light transmitted through thepowered smart glass is less than the third reference value, continuouslyapplying the electric power to the smart glass.
 15. The method accordingto claim 6, wherein determining the driving environment condition of thesmart glass comprises: when the driving environment condition is amanual mode, determining whether a user switch input is detected; whenthe user switch input is detected, determining whether the quantity oflight introduced is equal to or greater than a third reference value;when the quantity of light introduced is equal to or greater than thethird reference value, determining whether the quantity of lighttransmitted through the smart glass is less than the third referencevalue; and when the quantity of light transmitted through the smartglass is less than the third reference value, applying the electricpower to the smart glass.
 16. The method according to claim 15, furthercomprising: turning the electric power off when the quantity of lighttransmitted through the smart glass is equal to or more than the thirdreference value.
 17. The method according to claim 15, furthercomprising: when the quantity of light transmitted through the smartglass is equal to the third reference value, turning the electric poweroff.
 18. The method according to claim 15, wherein determining whetherthe quantity of light transmitted through the smart glass is less thanthe third reference value comprises: displaying an impossibility ofexecution when the quantity of light transmitted through the smart glassexceeds the third reference value.
 19. The method according to claim 6,wherein the driving environment condition is measured using at least oneof an auto light sensor, a rain sensor, a navigator, or an ambient lightsensor located inside the smart glass.